Project Summary/Abstract Sexual violence (SV) is a highly prevalent, significant public health problem resulting in serious health, economic, and social consequences. Like other forms of violence, SV is preventable. Through its Rape Prevention and Education (RPE) program, the CDC has funded states to strengthen the SV prevention efforts of community organizations. However, the evidence base for these efforts is weak, and how best to prevent SV perpetration remains unclear. Our study will rigorously evaluate an ongoing RPE-funded program, Wise Guys: The Next Level (WGNL), which addresses SV perpetration by addressing known risk and protective factors, such as rape culture and unhealthy masculinity, gender stereotyping, communication and consent in relationships. WGNL is based on an evidence-informed theory of change and is implemented by Children's Home Society of North Carolina (CHSNC), a well-established community-based organization that has been working with men and boys since the 1990s. CHS currently implements WGNL in numerous sites that serve boys and young men at high risk for SV perpetration. In Year 1, our research team will work with CHSNC and the North Carolina Coalition Against Sexual Assault, as well as our Research Advisory Board, to identify, refine, and document the core components and activities of WGNL and formalize its implementation by CHSNC personnel. In Years 2 to 4, we will use a cluster-randomized design to randomize WGNL implementation by site and time. A total of 520 participants will be enrolled. Participants will be evaluated at pre-program (baseline), immediate post-program (2-month), and 12-month follow-up. The evaluation will be designed to measure the effect of WGNL on the primary outcome of preventing SV perpetration and, secondarily, on preventing dating violence, bullying, sexual risk behavior, and harassment. We will document the implementation costs of WGNL to inform future research and SV prevention interventions. Our proposed research addresses several research priorities identified in the CDC Injury Research Agenda for 2009-2018, including ?evaluating approaches to prevent SV that target high-risk populations and shared risk factors with other health outcomes? and ?evaluating the effectiveness of SV prevention approaches with substantial uptake and informed by evidence, but without evaluation research evidence.? Our research team has a long history of collaboration with practitioners in the SV prevention community. Our use of a practice-informed evidence research paradigm will optimize dissemination of study results to the practitioner community, and increase the probability that this program, if found to be effective, can replicated with fidelity and sustainability in other communities.